Abstract : Hanon, C, Savarino, J, and Thomas, C. Blood lactate and acid-base balance of world-class amateur boxers after three 3-minute rounds in international competition. J Strength Cond Res 29(4): 942–946, 2015—To examine the blood metabolic responses of world-class boxers involved in international competition (Test match), 33 male boxers (mean 6 SD) competing internationally across all the official weight categories were studied on 2 different occasions: Test match 1 (team A against team B) and Test match 2 (team A against team C). Blood samples were collected after the third round for both Test matches for all teams except team B. For all Test matches and boxers, mean blood lactate concentration ([BLac]), bicarbonate concentration, hemo-globin O 2 saturation (SaO 2), partial pressure for CO 2 (PCO 2), and pH were 13.6 6 2.4 mmol$L 21 , 13.2 6 2.3 mmol$L 21 , 95.0 6 2.6%, 32.0 6 5.5 mm Hg, and 7.22 6 0.06 with 7/20 final pH values ,7.20. The intermediate category (60–64 kg) was characterized by the greatest [BLac] (14.8 6 2.9) compared with the heaviest and lighter boxers (;12 mmol$L 21). During the second match (team A again team C), a significant difference between pH, PCO 2 , and SaO 2 values was observed with no concomitant difference in [BLac] suggesting a better buffering capacity in team A. This result highlights the need for a well-developed anaerobic and buffering capacity and indicates that world-class boxers must be able to tolerate a substantial level of acidosis to produce high levels of boxing activity until the end of a match.